Metaslider is one of the most complete and prominent Slider solutions for WordPress.
However it lacks a few features inorder to meet WCAG 2.0 requirements.
Most of the issues are related to supporting users of Screen readers
- 4.1.2 – Name, Role, Value – Level A
For exemple: Using aria-labelledby to provide a name for user interface controls
- Changes to carousel items must be communicated to all users, including screen reader users.
For example: Announce the current item (Using WAI-ARIA Live region)
For a complete overview please refer to: https://www.w3.org/WAI/tutorials/carousels/